Oil separation in refrigerating apparatus



April 2, 1957 c. H. WURTZ OIL. SEPARATION IN REFRIGERATING APPARATUS Filed Jan. 5, 1954 INVENTOR.

C/ifford H. Wurlz W WI His Attorney United States Patent 01L SEPARATION IN REFRIGERATING APPARATUS Clifford H. Wurtz, Dayton, Ohio, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application January 5, 1954, Serial No. 402,291

5 Claims. (Cl. 62-117.75)

This invention relates to refrigerating apparatus and more particularly to an arrangement for separating the lubricant from the refrigerant at the outlet of the compressor.

It is now customary practice in many sealed motorcompressor units to convey the mixture of compressed refrigerant and oil out through a conduit which passes through one Wall of the motor-compressor housing and connects to a superheat removing coil which then reenters the housing so as to return the mixture to the housing where the lubricant is separated from the refrigerant. In addition to the connections for the superheat removing coil, another connection to the motor-compressor housing is then necessary through which the compressed refrigerant leaves the housing. Such a construction necessitate-s making three separate connections to the motorcompressor housing in addition to the suction connection. it is an object of this invention to eliminate the need for two of these connections without eliminating the superheat removing feature.

It is another object of this invention to provide a simple and inexpensive oil separator arrangement for use with sealed compressor units.

More particularly it is an object of this invention to provide a combination refrigerant outlet conduit, oil separator, and superheat removing means which requires only one connection to the compressor housing.

Further objects and advantages of the present invention will be apparent from the following description, ref erence being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings:

Figure l is a vertical sectional view partly diagrammatic showing the relationship between the combination oil separator and superheat removing device and the rest of the refrigerating system; and,

Figure 2 is a fragmentary sectional view showing a modified oil separator arrangement.

Referring now to Figure l of the drawing wherein a preferred embodiment of the invention has been shown, reference numeral generally designates a scaled hous ing in which a conventional motor 12 and compressor 14 are located. The refrigerant to be compressed enters the compressor 14 through the suction line 16 which passes through the bottom wall of the housing 16. The compressed refrigerant is discharged from the compressor through a discharge line 18 which terminates in the upper part of a combination oil separating and superheat removing housing 20 which is arranged as shown.

The housing 20 is in effect a large, round conduit which projects through the top wall of the compressor housing til and serves as the outlet connection through which the compressed refrigerant leaves the housing 10. For purposes of illustration, fins 22 have been shown on the outer surface of the housing 20 for dissipating heat from the compressed refrigerant and oil which discharges into the upper end of the housing as shown. The housing 20 contains a quantity of aggregate material 24 such as wire 2,787,136 Patented Apr. 2, 1957 mesh or steel wool which aids in separating the lubricant from the compressed refrigerant and also aids in transmitting heat from the compressed refrigerant to the outer walls of the housing 20.

It will be noted that the compressor refrigerant and oil is discharged into the upper end of the housing 20 and is required to return to the lower portion of the housing 24) in order to escape therefrom. In flowing downwardly therein heat will be removed therefrom and the oil will separate out from the compressed refrigerant and will drain down to the bottom outlet 26 provided at the bottom end of the housing 20. The compressed gas flows into the lower end of the refrigerant outlet line 28 from whence it flows to the condenser 30.

The condensed refrigerant is then fed to theevaporator 32 through the usual pressure regulating device 34. Insofar as this invention is concerned, the device 34 could be either a thermostatic expansion valve, an automatic expansion valve, a fixed restrictor, or any other type of refrigerant control means.

By virtue of the above described construction and arrangement of the housing 20 relative to the motorcompressor housing, it is obvious that the oil separator portion is in effect mounted externally of the motorcompressor housing and allows the separated lubricant to be returned to the motor-compressor housing in a cooled condition through the same aperture through which the compressed refrigerant leaves the housing. In this manner the construction shown eliminates the need for two extra connections to the motor-compressor housing which are required when using a conventional superheat removing coil.

Figure 2 of the drawing shows a slightly modified construction in which a pair of concentric tubular portions 4t) and 42 are arranged as shown. In this modification the compressed refrigerant conveying line 18 discharges into the lower end of a chamber formed between the tubular housing sections and 42 and is required to pass upwardly through this chamber and. to thereafter flow downwardly through the inside of the inner tubular section 42. The lubricant is free to drain down through the bottom end of the section 42 which is open as indicated at ts. and the refrigerant vapor leaves through the lower end of the suction line 28. It will be noted that in each of the constructions disclosed herein the oil is cooled exteriorly of the motor-compressor housing and is thereafter returned to the motor-compressor housing.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, as may come within the scope of the claims which follow.

What is claimed is as follows:

1. In combination, a compressor, a condenser, an evaporator, refrigerant floW connections between said compressor, condenser and evaporator, a housing for said compressor having an inlet opening in one wall thereof through which returning refrigerant vapor flows on its way from said evaporator to said compressor and having an outlet opening through which compressed refrigerant flows on its way from said compressor to said. condenser, an oil separator housing having a portion projecting through said last named opening and comprising a pair of concentric tubular elements in which the innermost tubular element is open at both ends with the lower end communicating with the interior of the compressor housing, means for discharging the compressed refrigerant leaving said compressor into the lower end of the space formed between said concentric tubular elements, and means for withdrawing the compressed refrigerant from the lower end of said inner tubular element.

2. In combination, a compressor, a condenser, an evaporator, refrigerant flow connections between said compressor, condenser and evaporator, a sheet metal housing for said compressor having an inlet opening in one wall thereof through which returning refrigerant vapor flows on its Way from said evaporator to said compressor and having an outlet opening through which compressed refrigerant flows on its way from said compressor to said condenser, a sheet metal oil separating housing disposed within said outlet opening, means for conveying refrigerant from said compressor to one end of said oil separator housing, and means for withdrawing the com-- pressed refrigerant from the other end of said oil separating housing, said oil separating housing having an oil return passage formed therein communicating with the interior of said compressor housing, said oil separating housing having aggregate material therein facilitating the separation of lubricant from the compressed refrigerant.

3. In combination, a'compressor, a motor for driving said compressor, a condenser, an evaporator, refrigerant fiow connections between said compressor, condenser and evaporator, a sheet metal housing for said motor and said compressor having an inlet opening in one wall thereof through which returning refrigerant vapor flows on its way from said evaporator to said compressor and having an outlet opening through which compressed refrigerant flows on its way from said compressor to said condenser, a sheet metal oil separating housing disposed within said outlet opening, means for conveying refrigerant from said compressor to one end of said oil separator housing, and means for withdrawing the compressed refrigerant from the other end of said oil sep 'arating housing, said oil separating housing having an oil return passage formed therein communicating with the interior of said motor and compressor housing, the oil returning to said motor and compressor housing passing through said outlet opening.

4. In combination, a motor, a compressor driven by said motor, a condenser, an evaporator, refrigerant flow connections between said compressor, condenser and evaporator, a housing for said motor and compressor having an inlet opening in one wall thereof through which re turning refrigerant vapor flows onits wayfrom said evaporator to said compressor and having an outlet opening through Which compressed refrigerant flows on its way from said compressor to said condenser, an oil separating housing having a portion projecting through said outlet opening and having'an outlet above said motor and compressor, means for conveying refrigerant from said compressor to the upper end of said oil separating housing, and means for withdrawing the compressed refrigerant from the lower end of said oil separating housing, said oil separating housing having an oil return passage at its lower end communicating with the interior of said motor and compressor housing.

5. In combination, a motor, a compressor driven by said motor, a condenser, an evaporator, refrigerant flow connections between said compressor, condenser and evaporator, a sheet metal housing for said motor and compressor having an inlet opening in one wall thereof through which returning refrigerant vapor flows on its way from said evaporator to said compressor and having an outlet opening through which compressed refrigerant flows on its way from said compressor to said condenser, tubular sheet metal oil separating and superheat removing housing having a portion projecting through said outlet opening, said housing having a bottom oil outlet arranged above said motor, means for conveying refrigerant from said compressor to the upper end of said oil separating housing, and means for withdrawing the compressed refrigerant from the lower end of said oil separating housing, said oil separating housing having heat dissipating fin means associated therewith eXteriorly of said compressor housing and having an oil return passage communicating with the interior of said compressor housing.

References Cited in the file of this patent UNITED STATES PATENTS 

